The present invention relates to an image display system for X-ray images, etc., and more particularly, relates to a display control method making it possible to display images of a combination suited for interpretation when the region of interest is specified, with the most appropriate arrangement and the best image quality.
Images utilized for medical purposes include X-ray images, CT (computerized tomography) images, ultrasonic images, etc., all of these images being utilized by physicians for the purpose of conducting diagnosis of diseases. Various systems have been devised in which these images are generally prepared on an on-line basis. In such systems, images are reproduced, for example, on a CRT display apparatus, diagnosis being enabled by observation of these images. With regard to X-ray images, for example, the dynamic range and resolution of the display images on a CRT display apparatus is not satisfactory, as compared with images developed on X-ray films. Consequently, it is necessary to set the display condition, such as gray level transformation and spatial frequency enhancement, to the most appropriate conditions, in accordance with the region of interest and the diagnosis purposes.
Japanese Patent Laid-Open No. 28144/1984 discloses an apparatus in which an X-ray image of a patient recorded on a recording medium such as storage phosphor is displayed as a visible image on another recording medium (e.g., photographic film) or on a display apparatus such as a CRT, automatically selecting the best suited display conditions (e.g., gray level and spatial frequency enhancement) by inputting data such as the portion and the shooting method.
The above prior art system is attended with the following problems:
(1) Diagnosis is performed using a plurality of images. Images taken by different shooting methods and in different directions of vision are observed and compared with each other. Or, after observing some portion (e.g., a front view of the entire chest), a region where there is some abnormality (e.g., the apex of a lung) is observed. Accordingly, a single diagnosis requires a number of input operations, selecting each time the regions of interest and the shooting methods. PA1 (2) The above input operation is conducted by manipulating the keyboard or pointing to the positions concerned on the displayed icon. In any case, the operator has to turn his gaze from the image of the patient he is obserbing so as to be able to manipulate the keyboard or perform the operation of pointing to the region of interest and the shooting method, and watching the above icon, which reduces the efficiency of the diagnosis.